1. Field
a floating thin film magnetic head and a method of manufacturing the same is provided.
2. Related Art
A floating thin film magnetic head includes a slider in which a magnetroresistance effect element or an inductive element and is incorporated. A flexure is made of a flexible metal sheet adhesively fixing the slider to a free end thereof. A load beam fixes the flexure. In the floating thin film magnetic head, when a recording medium stops, a lower surface of the slider contacts with a surface of the recording medium by an elastic force of the load beam, and when the recording medium begins to move, the slider floats from the surface of the recording medium by a floating force, which is produced by an airflow led between the slider and the surface of the recording medium along a moving direction of the recording medium. By maintaining such floated state, the thin film magnetic head performs a recording operation and a reproducing operation.
A reproducing element and a recording element are laminated on an air discharging end face of the slider. The reproducing element includes the magnetroresistance effect element in which a resistance according to an intensity of an external magnetic field changes and an electrode layer electrically connecting with the magnetroresistance effect element.
The recording element includes a lower core layer that is laminated by inserting a magnetic gap layer magnetically connected at a position that is retreated from a surface opposite to the recording medium (hereinafter, refer to “a medium facing surface”), an upper core layer, and a coil layer of which a recording magnetic field is applied to the upper core layer and the lower core layer. Such reproducing element and recording element are covered with a protective layer, which is made of an insulating material such as Al2O3 or the like.
The thin film magnetic head performs a reproducing operation by detecting a resistance change of the electrically connected magnetroresistance effect element, and performs a recording operation by producing a dielectric magnetic field in the lower core layer and the upper core layer by means of a power feeding toward the coil layer and applying a leakage magnetic field as the recording magnetic field from the magnetic gap layer to the recording medium.
During the recording and the reproducing operations of the thin film magnetic head, the temperature of the reproducing element rises by a current that flows into the magnetroresistance effect element, and the temperature of the recording element rises by an exothermic heat of the coil layer due to the current flowing into the coil layer.
As above-mentioned, since the reproducing element and the recording element are covered with the protective layer made of the insulating material, the heat of the reproducing element and the recording element are not emitted outward. The temperature of the reproducing element and the recording element is high. Due to the temperature rise of the reproducing element and the recording element, an overall structure of the thin film magnetic head that includes the reproducing element, the recording element, and the protective layer is thermally expanded to protrude from the medium facing surface. In the related art, in order to avoid of the contact the thin film magnetic head with the recording medium, various measures, of which the thin film magnetic head element structure is ground obliquely, or a tip of the thin film magnetic head element structure is provided with a notch, are employed.
The related art is disclosed in JP-A-10-49822 and JP-A-11-328643.
Recently, in order to cope with the high recording density of the recording medium, it is required that a floating distance (a distance between the surface of the recording medium and the reproducing element and the recording element) of the thin film magnetic head is set to less than 1.5 nm. As mentioned above, in a case where the floating distance becomes significantly smaller, it is very difficult to prevent the element structure protruding from the medium facing surface by the thermal expansion from contacting with the recording medium. The risks such as the damage of the recording medium and the magnetic information recorded on the recording medium and the damage of the element structure in itself further increase. In order to achieve the high recording density, a frequency of the current applied to the magnetroresistance effect element and the coil layer should be high. For example, the temperature of the recording element is mainly above 100° C., thus the protruding amount of the overall element structure is large.
Conventionally, the thin film magnetic head element structure is ground and the element structure is provided with a notch. Since a target floating distance of the thin film magnetic head is very small, a grinding error and a forming error of the notch have a large effect on the floating distance, and a variation between individuals increases.